Creating woodland islets to reconcile ecological restoration, conservation, and agricultural land use

Abstract

Restoration initiatives seek to address widespread deforestation and forest degradation, but face substantial problems. “Passive restoration”, whereby abandoned agricultural land undergoes secondary succession, is often slow, owing to biotic and abiotic limitations. “Active restoration”, chiefly accomplished by planting trees, can be very expensive if large areas are to be restored. We suggest “woodland islets” as an alternative way to achieve ecological restoration in extensive agricultural landscapes, particularly in low-productivity environments. This approach involves the planting of many small, dense blocks of native trees to enhance biodiversity and provide a range of ecosystem services. If the surrounding land is abandoned, the islets act as sources of woodland species and seed, which can accelerate woodland development. Alternatively, if the surrounding area is used for cultivation or pasture, the islets will increase the conservation value of the land and offer the potential for income generation. Here, we review existing approaches to woodland restoration and evaluate the relative strengths and weaknesses of the woodland islets approach.This research has been financed by the projects: EU INCO Programme (REFORLAN: EU INCO-CT-2006- 032132), UE Alpha Programme II-0411-FA-FCD-FI-FC, Spanish Ministry of Science and Education CGL2004-00355/BOS, Madrid Government S-0505/AMB/0355\ud (REMEDINAL), and UK RELU Award 227/0010 “FarmCAT”

Restoring forests: What constitutes success in the twenty-first century?

“…Spatial prioritization of restoration efforts according to cost-benefit analyses that include ecological risks is crucial (Lammerant et al 2013). At the landscape level, effective restoration can be accomplished, for example, by creating forest fragments strategically positioned to maximize the fulfillment of ecosystem services, including potential dispersion (Rey-Benayas et al 2008;Stanturf et al 2014). As described in the 1st Restoring Forests Congress, developing tools to evaluate and monitor restoration success objectively is essential to accurately track the cost-benefit outputs of restoration efforts, and to learn from past actions using an adaptive approach (Oliet and Jacobs 2012).…”

Predation and aridity slow down the spread of 21-year-old planted woodland islets in restored Mediterranean farmland

“…Natural forest regeneration or passive restoration of Mediterranean abandoned agricultural land is usually slow due to a number of limiting factors (Maestre et al 2003;Bonet and Pausas 2004;Vallejo et al 2006;Rey Benayas et al 2008a). Key constraints on the speed of regeneration include (1) dispersal limitation because seed sources are remote and dispersal vectors may be rare (Rey Benayas et al 2008a;Pons and Pausas 2007a;Zamora et al 2010;Ramos-Palacios et al 2014); (2) seed predation Pérez-Ramos and Marañón 2008;Gómez and Hódar 2008;Leiva and Fernández 2003); (3) biotic limitation such as competition from established woody vegetation and herbaceous vegetation (Rey Benayas et al 2005;Cuesta et al 2010a), and herbivory Puerta et al 2012); and (4) abiotic limitation such as low water availability, extreme temperatures, poor soil structure and low nutrient availability (Rey Benayas 1998;Cuesta et al 2010b).…”

“…Key constraints on the speed of regeneration include (1) dispersal limitation because seed sources are remote and dispersal vectors may be rare (Rey Benayas et al 2008a;Pons and Pausas 2007a;Zamora et al 2010;Ramos-Palacios et al 2014); (2) seed predation Pérez-Ramos and Marañón 2008;Gómez and Hódar 2008;Leiva and Fernández 2003); (3) biotic limitation such as competition from established woody vegetation and herbaceous vegetation (Rey Benayas et al 2005;Cuesta et al 2010a), and herbivory Puerta et al 2012); and (4) abiotic limitation such as low water availability, extreme temperatures, poor soil structure and low nutrient availability (Rey Benayas 1998;Cuesta et al 2010b). Intensification of land use has brought remnant areas of natural or semi-natural vegetation into mainstream agriculture and as a result many of such areas have been lost or severely degraded.…”

Nucleation in tropical ecological restoration

“…A new tendency of restoration practices focuses on models of conservation of biofunctionality and on systemic restoration by redirecting the degraded community toward its integration with the surrounding natural landscape, reflecting its stochastic processes and current resilience capacity (Whisenant, 1999;Reis et al, 2003;García et al, 2000;García and Zamora, 2003;Gómez-Aparicio et al 2004;Castro et al, 2004;Zamora et al, 2004;Griffith and Toy, 2005;Metzger, 2006;Bechara et al, 2007ab;Reis et al, 2007;Tres and Reis, 2007;Benayas et al, 2008). In this context, the main goal of this "point of vew" is to present restoration techniques based on nucleation.…”